body{
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    padding-top: 40px;
    padding-bottom: 40px;
    background-position: 50% 50%;
    background-attachment: fixed;
    transition: all 2s ease;
}
.container{
    user-select: none;
    width: 100%;
    max-width: 500px;
    min-width: 360px;
    min-height: 100px;
    background-color: rgba(0,0,0,0.3);
    border-radius: 10px;
    color: #fff;
    overflow: auto;
    position: absolute;
    left: 50%;
    top: 50%;
    width: auto;
    height: auto;
    transform: translate(-50%, -50%);
}